DE 20 2004 002 616 U1 discloses a generic water filter installation, a seawater filter installation in particular, comprising a water line as a fluid line and a filter connected between two line sections of the fluid line. Individual filter elements are provided with a filter surface located in the filter interior for filtering water. One line section forms a feed line to the filter for the water to be cleaned. The other line section forms a drain line for the filtered water. In the known solution, feeding and draining of the filter can be blocked relative to the water line with blocking means (valves). The filter interior can be heated by a heating means with the blocking means blocked to a setpoint temperature of more than 50° C., preferably approximately 60±5° C. for decontamination of the filter surface. Preferably, the filter is designed as a backflushing filter with a backflushing means for cleaning the filter surfaces in counterflow to the actual filtering direction.
Aboard ship, such as for example container ships, ballast water is pumped on board in a particular harbor or underway in certain waters to be able to equalize missing ship's ballast. Ballast equalization can be achieved while sailing for example by a decreasing amount of fuel and by taking on new seawater ballast and/or pumping seawater between the individual ballast chambers to level the ship. When a new harbor is being approached and ballast water is pumped out into the harbor basin to load the ship with new cargo, it cannot be precluded that living organisms taken aboard in the original harbor or underway will be discharged in the new port of call. Thus, in a type of biological tourism, foreign organisms become settled in the biotopes, where they in fact do not belong, with the result that they can displace native species to their complete extinction. This occurrence can lead to a serious environmental situation. In addition to viruses, fungi, algae, protozoa, and other microorganisms can also be transported at the same time in this way. However, tiny organisms can indeed also be transported at the same time, including mussels and the like.
With the known solution according to the German utility model, this biological contamination is controlled by heating all the parts located in the filter interior of the filter for a sufficient time interval to a high enough temperature, for example 60° C., to kill algae, microorganisms and other tiny organisms. With the corresponding backflushing process, the killed organisms are returned immediately to the original water and are not delivered into foreign water after a forthcoming voyage. By preference, the known solution calls for cleaning by superheated steam. As a result of the indicated high temperature and considering that salt water is heated, this decontamination is highly corrosive and leads to the corresponding corrosion damage, thus necessitating the use of expensive materials, such as duplex steels, titanium or the like. The known solution is biologically very compatible for the environment. In particular, no toxic contaminants are formed. Only temperature control for the heating means to be triggered and monitored is very complex, and requires correspondingly trained operators.
It had already been suggested in the prior art that the microorganisms in the filter fabrics of a filter be destroyed by oxidation technologies using UV radiation. Ozone, chlorine dioxide and other toxic contaminants are then formed which contraindicate industrial use. The described devices in the prior art need not be limited to seawater applications, but can fundamentally always be used wherever problems occur with respect to bacterial and organic contaminants, as can occur for example in water filtering in industrial facilities, such as power plants.